The invention relates to cane harvesters which sever cane sticks from their roots, cut the sticks into short pieces called billets, and deliver the billets to a wagon or other billet transport system. More specifically, the invention relates to an improved cleaning system for a cane harvester.
Sugar cane plants vary substantially from one part of the world to another due to soil, and climate conditions. However, the plant is characterized by having large green leaves in all parts of the world. Leaves die and fall from the plant from time to time and new leaves grow. The leaves which fall lay on the ground. It is common for the leaves on the ground to approach half a meter in depth. Normally, these leaves are burned before the cane is harvested. When the leaves on the ground burn, some of the leaves still growing on the plant also burn. Even after the leaves are burned there are, in many cases, so many leaves remaining on the plants that a harvester must travel slowly through a field so that the cleaning system is not overloaded. When a field cannot be burned before harvest, the capacity of current harvesters is substantially reduced. Cane fields cannot be burned when the cane is to be used for planting in another field, the field is too wet to burn, or when government authorities prohibit burning. Unburnt cane is commonly referred to as green cane.
Leaves mixed with cane billets, when the billets reach the mill, reduce the amount of sugar obtained from each ton of cane processed in the mill. It is, therefore, very important to clean the billets as well as possible before the billets reach the mill.